SwiftUI NSSearchField文本被卡住

Question

由于SwiftUI本机不支持macOS 11中的搜索组件，所以我正在包装NSSearchField。这主要是直到文本超出当前字段的宽度，在输入时通常会看到文本滚动。使用我的包装器不会发生这种情况，也不会使用我在网上找到的许多类似的片段。视图还不允许将光标移动到文本可见部分的末尾。

第一项是我的SearchBar，第二项是TextField。注意文本是如何在后面继续进行的(如预期的)。

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import SwiftUI

struct SearchBar: NSViewRepresentable {
    private var placeholder: String
    @Binding var text: String
    
    init(_ placeholder: String, text: Binding<String>) {
        self.placeholder = placeholder
        _text = text
    }
    

    class Coordinator: NSObject, NSSearchFieldDelegate {

        @Binding var text: String

        init(text: Binding<String>) {
            _text = text
        }
        
        func controlTextDidChange(_ obj: Notification) {
            if let searchField = obj.object as? NSSearchField {
                text = searchField.stringValue
            }
        }
    }

    func makeCoordinator() -> SearchBar.Coordinator {
        return Coordinator(text: $text)
    }

    func makeNSView(context: NSViewRepresentableContext<SearchBar>) -> NSSearchField {
        let searchField = NSSearchField(frame: .zero)
        searchField.delegate = context.coordinator
        searchField.placeholderString = placeholder
        return searchField
    }

    func updateNSView(_ nsView: NSSearchField, context: NSViewRepresentableContext<SearchBar>) {
        nsView.stringValue = text
    }
}

struct SearchBar_Previews: PreviewProvider {
    @State private static var text = ""

    static var previews: some View {
        SearchBar("Search", text: $text)
    }
}

Answer 1

您需要对NSSearchField进行子类化并启用isScrollable。

import SwiftUI

struct Searchbar: NSViewRepresentable {
    private var placeholder: String
    @Binding var text: String
    
    init(_ placeholder: String, text: Binding<String>) {
        self.placeholder = placeholder
        _text = text
    }
    
    
    class Coordinator: NSObject, NSSearchFieldDelegate {
        @Binding var text: String
        
        init(text: Binding<String>) {
            _text = text
        }
        
        func controlTextDidChange(_ obj: Notification) {
            guard let searchField = obj.object as? CustomSearchField else { return }
            text = searchField.stringValue
        }
    }
    
    func makeCoordinator() -> Searchbar.Coordinator {
        return Coordinator(text: $text)
    }
    
    func makeNSView(context: Context) -> CustomSearchField {
        let searchField = CustomSearchField(frame: .zero)
        
        // delegate
        searchField.delegate = context.coordinator
        // placeholder
        searchField.placeholderString = placeholder
        // layout
        searchField.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
        
        return searchField
    }
    
    func updateNSView(_ nsView: CustomSearchField, context: Context) {
        nsView.stringValue = text
    }
    
    class CustomSearchField: NSSearchField {
        override init(frame frameRect: NSRect) {
            super.init(frame: frameRect)
            
            self.cell = CustomSearchFieldCell(textCell: "")
        }
        
        required init?(coder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
        }
    }
    
    class CustomSearchFieldCell: NSSearchFieldCell {
        override init(textCell string: String) {
            super.init(textCell: string)
            
            self.isEditable = true
            self.isBordered = true
            self.drawsBackground = true
            self.isBezeled = true
            self.isSelectable = true
            self.isScrollable = true // <--- here!!
        }
        
        required init(coder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
        }
    }
}

struct SearchBar_Previews: PreviewProvider {
    @State private static var text = ""
    
    static var previews: some View {
        Searchbar("Search", text: $text)
                .preferredColorScheme(.light)
                .frame(width: 150)
    }
}